How do I snap an object to an empties world position in the bge
get an object from the scene named "Target"


scene = bge.logic.getCurrentScene()
objects = scene.objects
target = objects["Target"]



  get the sensor connected to the python controller


sensors = bge.logic.getCurrentController().sensors
sensor = sensors["sensor name"]



  when the sensor is triggered


if sensor.triggered:


or do you mean "when the sensor evaluates positive condition"? (Which makes more sense)

if sensor.positive:



  move its Owner (the player) to the "Target" object.


sensor.owner.worldPosition = target.worldPosition


I hope it helps

You can find more details on BGE Python in the BGE Guide to Python Coding